..We show here that using gene windows artificially enhances the correlation. The assertion that the expression of a given gene depends on the GC-content of the region where it is located is therefore not supported by the data...

No evidence for tissue-specific adaptation of synonymous codon usage in humans

..This demonstrates that variations of synonymous codon usage between tissue-specific genes expressed in different tissues are due to regional variations of substitution patterns and not to translational selection...

Evidence that functional transcription units cover at least half of the human genome